RF-based material identification systems and methods

Abstract

A system for material detection and identification includes an interface configured to access a material database associating each of a plurality of materials with one or more corresponding resonance frequencies; an RF transmitter configured to, for each material of at least a subset of the plurality of materials in the material database, transmit into an environment an RF signal at a first resonance frequency for the material; an RF receiver configured to receive a response signal from the environment for each RF signal; and a processor configured to analyze each response signal for resonance characteristics that indicate a presence of the material and identifying the material to a user if the presence of the material is indicated by the resonance characteristics.

What is claimed is: 
     
         1 . A method for identifying detected materials, the method comprising:
 accessing a material database that stores:
 respective associations of a plurality of materials with a corresponding resonance frequency, and 
 a priority for detecting each material from a subset of the materials that are associated with an application; 
   transmitting a radio frequency (RF) signal via an RF transmitter into an environment at a first resonance frequency corresponding to at least one material from the subset of the materials in order of the priority for the application in accordance with the material database;   receiving a response signal from the environment, the response signal corresponding to the RF signal transmitted at the first resonance frequency;   analyzing the response signal for resonance characteristics that indicate a presence of the at least one material in the environment;   calculating a mass of the at least one material based on at least one of an amplitude of the response signal and a distance between the RF transmitter and the at least one material in the environment; and   displaying a graphic interface reflecting:
 the presence of each material in the environment as indicated by the resonance characteristics, and 
 the corresponding mass of each present material. 
   
     
     
         2 . The method of  claim 1 , further comprising:
 transmitting a second resonance frequency into the environment, the second resonance frequency corresponding to at least one other material from the subset of materials in accordance with the material database; and   analyzing a received response signal corresponding to the RF signal transmitted at the second resonance frequency for resonance characteristics that indicate the presence of the at least one other material from the subset of the materials.   
     
     
         3 . The method of  claim 2 , further comprising:
 sequentially transmitting into the environment one or more next resonance frequencies corresponding to one or more next materials from the subset of the materials in the order of the priority for the application in accordance with the materials database; and   analyzing any response signal received for each sequential transmission.   
     
     
         4 . The method of  claim 1 , wherein analyzing the response signal is further based on contextual data when the response signal includes ambiguous resonance characteristics. 
     
     
         5 . The method of  claim 1 , wherein analyzing the response signal includes analyzing a timing of receipt of the response signal. 
     
     
         6 . The method of  claim 1 , wherein analyzing the response signal is further based on input from at least one other sensing modality when the response signal includes ambiguous resonance characteristics. 
     
     
         7 . The method of  claim 6 , wherein the at least one other sensing modality includes one or more of a mass spectrometer, an x-ray diffraction analyzer, an x-ray fluorescence analyzer, a magnetic resonance imaging (MRI) scanner, a computed tomography (CT) scanner, and an optical imager. 
     
     
         8 . The method of  claim 1 , wherein analyzing the response signal includes comparing signal strengths at a plurality of frequencies for the at least one material. 
     
     
         9 . The method of  claim 1 , further comprising recognizing patterns between the at least one material and the resonance characteristics that indicate the presence of the at least one material using a machine learning algorithm. 
     
     
         10 . The method of  claim 1 , further comprising:
 calculating a direction of the at least one material relative to the RF transmitter based on triangulating the response signal received by a multi-point receiving antenna; and   displaying an indication of the direction of the at least one material.   
     
     
         11 . The method of  claim 1 , further comprising calculating the distance between the RF transmitter and the at least one material using time-of-flight data of the RF signal and the response signal. 
     
     
         12 . The method of  claim 11 , further comprising adjusting the time-of-flight data based on media through which the RF signal and the response signal must travel. 
     
     
         13 . A system for identifying detected materials, the system comprising:
 a material database that stores:
 respective associations of a plurality of materials with a corresponding resonance frequency, and 
 a priority for detecting each material from a subset of the materials that are associated with an application; 
   a radio frequency (RF) transmitter that transmits an RF signal at a first resonance frequency into an environment, the first resonance frequency corresponding to at least one material from the subset of the materials in order of the priority for the application in accordance with the material database;   an RF receiver that receives a response signal from the environment, the response signal corresponding to the transmitted RF signal at the first resonance frequency;   a processor that executes instructions from memory, wherein the processor executes the instructions to:
 analyze the response signal for resonance characteristics that indicate a presence of the at least one material in the environment, and 
 calculate a mass of the at least one material based on an amplitude of the response signal and a distance between the RF transmitter and the at least one material in the environment; and 
   a display device that displays a graphic interface reflecting:
 the presence of each material in the environment as indicated by the resonance characteristics, and 
 the corresponding mass of each present material. 
   
     
     
         14 . The system of  claim 13 , wherein the RF transmitter further transmits into the environment at least one RF signal at a second resonance frequency for the at least one material when no materials are identified in response to the first resonance frequency. 
     
     
         15 . The system of  claim 13 , wherein the processor analyzes the response signal further based on contextual data to refine a likelihood of specific materials being present when no materials are identified are detected. 
     
     
         16 . The system of  claim 13 , wherein the processor analyzes the response signal by analyzing at least one of a timing of receipt of the response signal. 
     
     
         17 . The system of  claim 13 , wherein the processor analyzes the response signal further based on input from at least one other sensing modality when the response signal includes ambiguous resonance characteristics. 
     
     
         18 . The system of  claim 17 , wherein the at least one other sensing modality includes one or more of a mass spectrometer, an x-ray diffraction analyzer, an x-ray fluorescence analyzer, a magnetic resonance imaging (MRI) scanner, a computed tomography (CT) scanner, and an optical imager. 
     
     
         19 . The system of  claim 13 , further comprising a machine learning module executable by the processor to recognize patterns between the at least one material and the resonance characteristics that indicate the presence of the at least one material. 
     
     
         20 . The system of  claim 13 , wherein the RF receiver includes a multi-point receiving antenna for triangulating the response signal. 
     
     
         21 . The system of  claim 13 , wherein the processor executes further instructions to calculate the distance between the RF transmitter and the at least one material using time-of-flight data of the RF signal and the response signal. 
     
     
         22 . The system of  claim 21 , wherein the processor executes further instructions to calculate the distance between the RF transmitter and the at least one material using the time-of-flight data by adjusting the time-of-flight data based on media through which the RF signal and the response signal must travel.